Improving tools and methods to understand the implications of volatile chemical product usage on public health

Abstract:

Volatile chemical product (VCP) usage results in direct human exposure during and immediately after product use. In addition, reactive organic carbon that escapes into ambient air can result in far-field direct exposure via inhalation or deposition and react to form secondary pollutants such as ozone and fine particulate matter (PM_2.5). Multiple areas of method development are underway to improve our estimates of how VCPs impact health. They include development of ambient air emission inventories using bottom-up information and near-field modeling as well as identification of atmospheric chemistry leading to secondary organic aerosol (SOA). In this work, we present progress on each of these paths. We find that both near-field and ambient air quality modeling have overlapping data needs and can leverage information from each other. Specifically, ambient air measurements of PM_2.5 and O₃ can provide top-down constraints on VCP emissions while bottom-up inventory methods and near-field exposure models connect volatilization to product usage. We also find that while current chemical transport models such as the Community Multiscale Air Quality (CMAQ) model include VCP emissions chemistry, several assumptions likely lead to missing SOA in the system. Updating these tools is critical to improve predictions of SOA which is a driver of the negative health implications of ambient PM_2.5.